Serum thyroxine and thyrotropin concentrations decrease with severity of nonthyroidal illness in cats and predict 30-day survival outcome

Background

In cats, nonthyroidal illness affects serum thyroid hormone concentrations. Serum thyroxine (T₄) and triiodothyronine (T₃) concentrations commonly decrease, whereas free T₄ (fT₄) concentrations vary unpredictably. Limited information exists regarding effects on serum thyrotropin (thyroid‐stimulating hormone [TSH]) concentrations in cats with nonthyroidal illness syndrome (NTIS).

Objectives

To characterize alterations in thyroid function that develop in cats with NTIS and to correlate these alterations with severity and outcome of the nonthyroidal illness.

Animals

Two hundred and twenty‐two cats with NTIS and 380 clinically normal cats of similar age and sex.

Methods

Prospective, cross‐sectional study. All cats had serum T₄, T₃, free T₄, and TSH concentrations measured. Cats were grouped based on illness severity and 30‐day survival.

Results

Cats with NTIS had lower serum T₄ and T₃ concentrations than did normal cats (P < .001). Serum fT₄ and TSH concentrations did not differ between groups. Serum T₄, T₃, and fT₄ concentrations progressively decreased with increasing disease severity (P < .001). The 56 cats that died had lower T₄, T₃, and TSH concentrations than did the 166 survivors, with no difference in fT₄ concentration. Multivariable logistic regression modeling indicated that serum T₄ and TSH concentrations both predicted survival (P < .02).

Conclusions and Clinical Importance

Cats with NTIS commonly develop low serum T₄, T₃, and TSH concentrations, the prevalence and extent of which increases with disease severity. Clinicians should consider evaluating thyroid function in cats with severe NTIS, because doing so could help determine probability of successful treatment responses before investing considerable time, effort, and finances in addressing the underlying disease.

Pituitary Gangliocytoma Producing TSH and TRH: A Review of "Gangliocytomas of the Sellar Region"

PURPOSE

Pituitary gangliocytomas (GCs) are rare neuronal tumors that present with endocrinological disorders, such as acromegaly, amenorrhea-galactorrhea syndrome, and Cushing's disease. Most pituitary GCs coexist with pituitary adenomas pathologically and are diagnosed as mixed gangliocytoma-adenomas. Herein, we report a case of 45-year-old man who presented with the syndrome of inappropriate secretion of thyroid-stimulating hormone (SITSH) and discuss the pathogenesis of pituitary GCs.

METHODS

Pituitary magnetic resonance imaging showed an 8-mm homogeneous and poorly enhanced mass inside the pituitary gland. Endoscopic transsphenoidal surgery was performed under a preoperative diagnosis of thyrotroph adenoma. However, the tumor was finally diagnosed as gangliocytoma without an adenomatous component. The tumor was further analyzed via immunohistochemistry and electron microscopy. Additionally, we searched MEDLINE and PubMed for previously published cases of isolated pituitary GCs and analyzed the reported clinicopathological findings.

RESULTS

The patient showed complete clinical and endocrinological recovery after an operation. The tumor was positive for thyrotropin (TSH), TSH-releasing hormone (TRH), Pit-1, GATA-2, and most neuronal markers. Electron microscopy demonstrated the presence of intracytoplasmic secretory granules and neuronal processes. Co-secreting hypothalamic and pituitary hormone inside the tumor indicated autocrine/paracrine endocrinological stimulation.

CONCLUSION

Herein, we report a case of SITSH caused by an isolated pituitary gangliocytoma, expressing both TSH and TRH, which, to our best knowledge, is the first reported case of such a condition. The multidirectional differentiation and multihormonal endocrine characteristics of these tumors indicate that they are a member of neuroendocrine neoplasms, further supporting that they are derived from neural crest cells.

Causal associations of thyroid function and dysfunction with overall, breast and thyroid cancer: A two-sample Mendelian randomization study

Whether thyroid dysfunction plays a causal role in the development of cancer remains inconclusive. We conducted a two-sample Mendelian randomization study to investigate the associations between genetic predisposition to thyroid dysfunction and 22 site-specific cancers. Single-nucleotide polymorphisms associated with four traits of thyroid function were selected from a genome-wide association meta-analysis with up to 72,167 European-descent individuals. Summary-level data for breast cancer and 21 other cancers were extracted from the Breast Cancer Association Consortium (122,977 breast cancer cases and 105,974 controls) and UK Biobank (367,643 individuals). For breast cancer, a meta-analysis was performed using data from both sources. Genetically predicted thyroid dysfunction was associated with breast cancer, with similar patterns of associations in the Breast Cancer Association Consortium and UK Biobank. The combined odds ratios of breast cancer were 0.94 (0.91-0.98; p = 0.007) per genetically predicted one standard deviation increase in TSH levels, 0.96 (0.91-1.00; p = 0.053) for genetic predisposition to hypothyroidism, 1.04 (1.01-1.07; p = 0.005) for genetic predisposition to hyperthyroidism and 1.07 (1.02-1.12; p = 0.003) per genetically predicted one standard deviation increase in free thyroxine levels. Genetically predicted TSH levels and hypothyroidism were inversely with thyroid cancer; the odds ratios were 0.47 (0.30-0.73; p = 0.001) and 0.70 (0.51-0.98; p = 0.038), respectively. Our study provides evidence of a causal association between thyroid dysfunction and breast cancer (mainly ER-positive tumors) risk. The role of TSH and hypothyroidism for thyroid cancer and the associations between thyroid dysfunction and other cancers need further exploration.

Importance of thyroid-stimulating hormone levels in liver disease

Objectives Recently, several studies have reported the association between elevation of thyroid-stimulating hormone (TSH) levels and liver disease, especially, non-alcoholic fatty liver disease (NAFLD). We aimed to evaluate the incidence and risk factors of TSH elevation in patients with liver disease. Methods We retrospectively reviewed the data of patients aged <18 years who were diagnosed with liver disease between January 2015 and March 2019. Results Among the 77 patients, 17 (22.1%) had subclinical hypothyroidism and 3 (17.6%) progressed to overt hypothyroidism. A total of 26 (33.8%) patients had NAFLD, and 6 (23.1%) had subclinical hypothyroidism. The ultrasound grade of liver steatosis was not related to the elevation of TSH levels. The median age was significantly younger in patients with TSH elevation (5 vs. 9 years, p = 0.017). Albumin levels were significantly decreased (3.9 vs. 4.3 g/dL, p = 0.007), and total bilirubin levels were elevated (2.2 vs. 0.6 mg/dL, p = 0.001) in patients with subclinical hypothyroidism. Conclusions TSH elevation commonly occurs in patients with liver disease, especially those with younger age. The cause of liver disease was not a risk factor for TSH elevation.

Plasma branched chain amino acids are lower in short-term profound hypothyroidism and increase in response to thyroid hormone supplementation

Branched chain amino acids (BCAA) are implicated in the pathogenesis of cardiometabolic diseases conceivably by affecting insulin resistance and mitochondrial dysfunction. Circulating BCAA levels may predict (subclinical) atherosclerosis, diabetes and hypertension development but the factors involved in BCAA regulation are incompletely understood. Given the key role of thyroid hormones on many metabolic processes including protein metabolism, we aimed to determine effects of thyroid dysfunction on circulating BCAA. Effects of short-term profound hypothyroidism on plasma BCAA were determined in 17 patients who had undergone total thyroidectomy for differentiated thyroid carcinoma. Patients were studied during hypothyroidism, i.e. after thyroidectomy, and after thyroid hormone supplementation. Plasma BCAA (sum of valine, leucine and isoleucine) and alanine were measured by nuclear magnetic resonance spectroscopy. During hypothyroidism (median thyroid-stimulating hormone 81 (IQR 67-120.5) mU/L), plasma BCAA were lower (255 (IQR 222-289) µmol/L) compared to a euthyroid reference population (n = 5579; 377 µmol/L (2.5th to 97.5th percentile 258-548), p < 0.001). After 20 weeks of thyroid hormone supplementation (thyroid-stimulating hormone 0.03 (IQR 0.01-0.14 mU/L) plasma BCAA had increased (328 (IQR 272-392) µmol/L, p = .001), but plasma alanine concentrations were unaltered (p = .50). Changes in body weight in response to thyroid hormone supplementation were correlated with changes in plasma BCAA (r = 0.721 p = .001, but not with changes in cholesterol or glucose (p > .80). In conclusion, plasma BCAA concentrations are lower during short-term profound hypothyroidism in humans, and increase in response to thyroid hormone supplementation. Changes in BCAA and in body weight after reversal of the hypothyroid state appear to be interrelated.

Influence of General Mineral Condition on Collagen-Guided Alveolar Crest Augmentation

The local regeneration of bone defects is regulated by general hormone, enzyme, ion, and vitamin levels. General diseases and dysregulation of the human mineral system can impact this process, even in alveolar crest. The aim of this study is to investigate a relation between bone density, measured in two-dimensional X-rays, and general mineral condition of patients. The study included 42 patients on whom tooth extractions were performed. Data were divided into two groups: the region where collagen scaffold (BRM) was used and the reference region of intact normal bone (REF). Two-dimensional intraoral radiographs were taken in all cases just after the surgery (00 M) and 12 months later (12 M). Thyrotropin (TSH), parathormone (PTH), Ca²⁺ in serum, HbA1c, vitamin 25(OH)D₃, and spine densitometry were checked. Digital texture analysis in MaZda 4.6 software was done. Texture Index (TI: BRM 1.66 ± 0.34 in 00 M, 1.51 ± 0.41 in 12 M, and REF 1.72 ± 0.28) and Bone Index (BI: BRM 0.73 ± 0.17 in 00 M, 0.65 ± 0.22 41 in 12 M, and REF 0.80 ± 0.14) were calculated to evaluate bone regeneration process after 12 months of healing (TI (p < 0.05) and BI (p < 0.01) are lower in BRM 12 M than in REF). This showed a relation between BI and TSH (R² = 26%, p < 0.05), as well as a between BI and patient age (R² = 65%, p < 0.001), and a weak relation between TI and TSH level (R² = 10%, p < 0.05). This study proved that a collagen scaffold can be successfully used in alveolar crest regeneration, especially in patients with a high normal level of TSH in the middle-aged population.

Small Cell Variant of Medullary Thyroid Carcinoma: A Possible Treatment

Small cell variant of medullary thyroid carcinoma is an extremely rare histologic entity with a paucity of data. As such, there is a lack of literature and clinical experience regarding this disease. In this report, we examine a case of small cell variant of medullary thyroid carcinoma that presented with intractable nausea, vomiting and diarrhea. While these symptoms were essentially refractory to the standard symptomatic treatment, further laboratory analysis revealed dramatically elevated calcitonin levels and mildly raised thyroid-stimulating hormone levels. Interestingly, repletion of thyroid hormone and treatment with lanreotide resulted in an abatement of our patient’s symptoms. This temporal clinical improvement highly suggests a potential role involving thyroid-stimulating hormone and calcitonin levels in the pathogenesis of this disease, and consequently suggests a role for thyroxine in treating the associated gastrointestinal symptoms. 

The intramolecular agonist is obligate for activation of glycoprotein hormone receptors

In contrast to most rhodopsin-like G protein-coupled receptors, the glycoprotein hormone receptors (GPHR) have a large extracellular N-terminus for hormone binding. The hormones do not directly activate the transmembrane domain but mediate their action via a, thus, far only partially known Tethered Agonistic LIgand (TALI). The existence of such an intramolecular agonist was initially indicated by site-directed mutation studies and activating peptides derived from the extracellular hinge region. It is still unknown precisely how TALI is involved in intramolecular signal transmission. We combined systematic mutagenesis studies at the luteinizing hormone receptor and the thyroid-stimulating hormone receptor (TSHR), stimulation with a drug-like agonist (E2) of the TSHR, and structural homology modeling to unravel the functional and structural properties defining the TALI region. Here, we report that TALI (a) is predisposed to constitutively activate GPHR, (b) can by itself rearrange GPHR into a fully active conformation, (c) stabilizes active GPHR conformation, and (d) is not involved in activation of the TSHR by E2. In the active state conformation, TALI forms specific interactions between the N-terminus and the transmembrane domain. We show that stabilization of an active state is dependent on TALI, including activation by hormones and constitutively activating mutations.

[Hormones of stress-response system in alcohol dependence: the ability to predict duration of remission]

OBJECTIVE

To determine the spectrum of hormones of the stress-realizing system in the time course of therapy of withdrawal syndrome and post-withdrawal state and analyze their possible relationships with the duration of therapeutic remission in patients with alcohol dependence.

MATERIAL AND METHODS

The examination included 74 men admitted in the clinic at Mental Health Research Institute NRMC diagnosed as having «Mental and behavioral disorders due to use of alcohol» (dependence syndrome F10.21 and withdrawal state - F10.30) according to ICD-10. The control group included 35 men matched in age with patients. Concentration of cortisol, testosterone, and thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4) were determined by immunoenzyme method (IEM), in patients - at two points: point 1 - by day 3-5 of the admission in the clinic in the withdrawal syndrome state after alcohol detoxification; point 2 - by day 15-17 of the anti-alcohol therapy.

RESULTS

In the general group of patients with alcohol dependence the elevation of the level of cortisol in comparison with control was established (p_c<0,0001 at both points) and increase of concentration at point 2 (p=0,0253 to point 1). Concentration of testosterone at point 1 exceeded the level of control (p_c=0,0203), at point 2 decreased up to control values and in relation to point 1 (p=0,0004). In relation to control the level of TSH in patients was decreased at point 1 (p_c=0,0077); the concentration of fT3 and fT4 was reliably decreased at both points; concentration of fT4 decreased further in the process of the therapy of the post-withdrawal state (p=0,0003 to point 1). According to the duration of the last therapeutic remission, two groups of patients were formed: those with unstable remission (up to 6 months) and with the formed stable remission (1 year or more). A comparative analysis of the concentration of cortisol and testosterone in blood serum taken in patients at point 1 revealed a significant excess of testosterone in the group with unstable remission, both in relation to the control (p_c=0,0239) and to the indicator in the group of patients with stable remission (p=0,0159).

CONCLUSION

Dysfunctions in the spectrum of stress-realizing hormones in patients with alcohol dependence in the time course of the therapy for withdrawal syndrome and post-withdrawal state were revealed, the main of which are high level of cortisol, testosterone, reduction of secretion of free thyroxine and free triiodothyronine. Patients with unstable therapeutic remission are characterized by a high concentration of testosterone after alcohol detoxification, which allows us to consider testosterone as a biological criterion that can increase the accuracy of prediction of the duration of remission after anti-alcohol therapy.

The relationships between thyroid-stimulating hormone and/or dopamine levels in peripheral blood and IQ in children with different urinary iodine concentrations

Environmental iodine deficiency or excess can lead to inappropriate iodine nutrition in the population. Little research has been performed to determine whether changes in thyroid-stimulating hormone (TSH) and/or dopamine (DA) concentrations in peripheral blood are involved in intellectual impairment caused by inappropriate iodine nutrition. 498 children aged 7-12 from areas with different water iodine concentrations were included in the study. Children's intelligence and levels of urinary iodine and fluoride, TSH, free triiodothyronine (FT₃), free thyroxine (FT₄), and DA were evaluated. The relationship between TSH and/or DA levels and intelligence quotient (IQ) in all participants and in the population with different urinary iodine concentrations (UIC) was evaluated by multivariate regression analysis. The proportion of people with low average and lower intelligence in UIC ≥ 300 μg/L group was significantly higher than that in control group but only a positive correlation was found between DA and IQ in the population with UIC < 100 μg/L (bootstrapped estimation P = 0.032). TSH and/or DA in peripheral blood may be not involved in the progressive decline in intelligence caused by iodine excess but DA had positive correlation with intelligence in iodine deficiency group, and no relationship between TSH concentration and IQ was found in the general population or in different UIC groups.

Mating Enhances Expression of Hormonal and Trophic Factors in the Midbrain of Female Rats

Among female rats, mating enhances neurosteroid formation in the midbrain ventral tegmental area (VTA; independent of peripheral steroid-secreting glands, ovaries, and adrenals). The sources/targets for these actions are not well understood. In Experiment 1, proestrous rats engaged in a mating paradigm, or did not, and the midbrains had been assessed via the Affymetrix rat genome microarrays. In Experiment 2, the influence of gonadal and adrenal glands on the expression of these genes was assessed in rats that were proestrous, ovariectomized (OVX), or OVX and adrenalectomized (ADX). The microarrays revealed 53 target genes that were significantly up-regulated (>2.0-fold change) in response to mating. Mating significantly enhanced the midbrain mRNA expression of genes involved in hormonal and trophic actions: Gh1, S100g, and Klk1b3 in proestrous, but not OVX and/or ADX, rats; Fshb in all but OVX/ADX rats; and lutenizing hormone β and thyroid-stimulating hormone (TSH) β in all rats. Thus, mating enhances midbrain gene expression independent and dependent of peripheral glands.

Reference intervals for thyroid-stimulating hormone and thyroid hormones using the access TSH 3rd IS method in China

Background

To calculate the reference intervals for thyroid‐stimulating hormone (TSH) and thyroid hormones using the Access TSH 3rd IS method and evaluate the differences between age and genders in Chinese populations.

Methods

This study collected 349 serum samples of healthy subjects were from Shengli Oilfield Central Hospital in China. Subjects who tested positive for thyroid peroxidase antibody or thyroglobulin antibody were excluded. Accordingly, 313 subjects were included for establishing reference intervals for the thyroid hormones. The serum concentrations of TSH, total and free thyroxine (TT4 and FT4), and total and free triiodothyronine (TT3 and FT3) were measured using the Access TSH 3rd IS method. The 2.5th and 97.5th percentiles or mean with standard deviation were calculated as the reference interval as appropriate.

Results

The reference intervals for TSH, FT4, FT3, TT4, and TT3 calculated in present study were 0.61‐4.16 mIU/L, 0.67‐1.11 ng/dL, 2.63‐4.33 pg/mL, 5.56‐11.33 μg/dL, and 0.72‐1.32 ng/mL, respectively. The FT3, TT4, and TT3 levels in males were significantly higher than in females (P < .05), while TSH levels in males were significantly lower than in females (P < .05). The levels of FT3 in subjects with the age of less than 30 years were significantly higher than other groups (P < .05).

Conclusion

The present study provided a valid basis for the reference intervals for TSH, FT4, FT3, TT4, and TT3 in Chinese populations. In addition, this present study indicated that age and gender should be considered in diagnostic evaluation of thyroid diseases.

Pituitary Hyperplasia, Hormonal Changes and Prolactinoma Development in Males Exposed to Estrogens-An Insight From Translational Studies

Estrogen signaling plays an important role in pituitary development and function. In sensitive rat or mice strains of both sexes, estrogen treatments promote lactotropic cell proliferation and induce the formation of pituitary adenomas (dominantly prolactin or growth-hormone-secreting ones). In male patients receiving estrogen, treatment does not necessarily result in pituitary hyperplasia, hyperprolactinemia or adenoma development. In this review, we comprehensively analyze the mechanisms of estrogen action upon their application in male animal models comparing it with available data in human subjects. Sex-specific molecular targets of estrogen action in lactotropic (PRL) cells are highlighted in the context of their proliferative and secretory activity. In addition, putative effects of estradiol on the cellular/tumor microenvironment and the contribution of postnatal pituitary progenitor/stem cells and transdifferentiation processes to prolactinoma development have been analyzed. Finally, estrogen-induced morphological and hormone-secreting changes in pituitary thyrotropic (TSH) and adrenocorticotropic (ACTH) cells are discussed, as well as the putative role of the thyroid and/or glucocorticoid hormones in prolactinoma development, based on the current scarce literature.

Immediate postoperative measurement of thyroid-stimulating hormone as an early predictor of remission in thyroid-stimulating hormone-secreting pituitary adenomas

OBJECTIVE

Thyroid-stimulating hormone (TSH)-secreting pituitary adenoma (TSHoma) is a rare type of pituitary adenoma; thus, little is known about TSHomas. The purpose of this study was to analyze clinical characteristics and therapeutic outcomes of TSHomas based on a single-center experience. The authors also searched for reliable preoperative and early postoperative factors that could predict long-term endocrinological remission.

METHODS

The clinical, radiological, and pathological characteristics and surgical and endocrinological outcomes of 31 consecutive cases of TSHomas that were surgically treated between 2005 and 2017 were reviewed retrospectively. Preoperative factors were evaluated for their ability to predict long-term remission by comparing remission and nonremission groups. TSH and free thyroxine levels were measured at 2, 6, 12, 18, and 24 hours after surgery to determine whether they could predict long-term remission.

RESULTS

Gross-total removal of tumor was achieved in 28 patients (90.3%), and 26 patients (83.9%) achieved endocrinological remission by surgery alone based on long-term endocrinological follow-up (median 50 months, range 32-81 months). The majority of the tumors were solid (21/31, 67.7%), and en bloc resection was possible in 16 patients (51.6%). Larger tumor size and tumor invasion into cavernous sinus and sphenoid sinus were strong predictors of lower rates of endocrinological remission. Immediate postoperative TSH level at 12 hours after surgery was the strongest predictor, with a 0.62 μIU/mL cutoff. Postoperative complications included CSF rhinorrhea in one patient and epistaxis in another patient, who underwent additional surgical treatment for the complications.

CONCLUSIONS

Tumor size and extent are major prognostic factors for both extent of resection and endocrinological remission. The consistency of TSHomas was more likely to be solid, which makes extracapsular dissection more feasible. Long-term remission of TSHomas could be predicted even during the early postoperative period.

Reference intervals for thyroid-stimulating hormone, free thyroxine, and free triiodothyronine in elderly Chinese persons

Background Thyroid hormone levels are essential for diagnosing and monitoring thyroid diseases. However, their reference intervals (RIs) in elderly Chinese individuals remain unclear. We aimed to identify factors affecting thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) levels using clinical "big data" to establish hormone level RIs for elderly Chinese individuals. Methods We examined 6781, 6772, and 6524 subjects aged ≥65 years who underwent FT3, FT4, and TSH tests, respectively, at the Peking Union Medical College Hospital between September 1, 2013, and August 31, 2016. Hormones were measured using an automated immunoassay analyzer (ADVIA Centaur XP). RIs were established using the Clinical Laboratory Standards Institute document C28-A3 guidelines. Results The median TSH was significantly higher in women than in men; the opposite was true for median FT3 and FT4 levels. No differences were observed in TSH or FT4 by age in either sex or overall; FT3 levels significantly decreased with age. Seasonal differences were observed in TSH and FT3 levels but not FT4 levels; the median TSH was the highest in winter and lowest in summer, whereas the median FT3 was the lowest in summer (albeit not significantly). RIs for TSH were 0.53-5.24 and 0.335-5.73 mIU/L for men and women, respectively; those for FT3 were 3.76-5.71, 3.60-5.42, and 3.36-5.27 pmol/L in 64- to 74-, 75- to 84-, and 85- to 96-year-old subjects, respectively. The RI for FT4 was 11.70-20.28 pmol/L. Conclusions RIs for TSH in elderly individuals were sex specific, whereas those for FT3 were age specific.

Association between thyroid hormone parameters during early pregnancy and gestational hypertension: a prospective cohort study

Objective

Thyroid dysfunction may play a role in the development of gestational hypertension. However, this relationship remains unclear. This study was performed to evaluate the association between thyroid hormone parameters during early pregnancy and gestational hypertension.

Methods

Women with singleton pregnancies were recruited into this prospective cohort study at 9 to 13 gestational weeks, and their serum thyroid-stimulating hormone, free thyroxine, and free triiodothyronine concentrations were measured using electrochemiluminescence immunoassays. In total, 1226 participants were included in the final analysis.

Results

Of the 1226 participants, 81 subsequently developed gestational hypertension (overall incidence of 6.6%). Compared with women with euthyroidism, both pregnant women with hypothyroidism and those with subclinical hypothyroidism had an increased risk of gestational hypertension (adjusted odds ratio [OR], 3.61; 95% confidence interval [CI], 1.52–8.57 and OR, 2.24; 95% CI, 1.06–4.72, respectively). When the thyroid-stimulating hormone and free thyroxine concentrations were analyzed by quintiles, the women in the highest thyroid-stimulating hormone quintile had a higher risk of gestational hypertension (adjusted OR, 4.22; 95% CI, 1.78–9.05) than the women in the middle quintile.

Conclusion

Our results suggest that hypothyroidism, subclinical hypothyroidism, and a high thyroid-stimulating hormone concentration during early pregnancy are risk factors for gestational hypertension.

Associations Between Maternal Thyroid Function and Birth Outcomes in Chinese Mother-Child Dyads: A Retrospective Cohort Study

OBJECTIVE

Although research suggests a close association between maternal thyroid function and birth outcomes, no clear conclusion has been reached. We aimed to explore this potential association in a retrospective cohort study.

METHODS

This study included 8985 mother-child dyads. The maternal serum free tetraiodothyronine (FT4), thyroid-stimulating hormone (TSH), and thyroid peroxidase antibody (TPO Ab) concentrations and birth outcome data were reviewed from medical records. Subjects with TPO Ab concentrations of >34 and ≤34 IU/ml were classified into the TPO Ab positivity (+) and TPO Ab negativity (-) groups, respectively.

RESULTS

Compared with subjects in the normal group (0.1 ≤ TSH < 2.5 mIU/L and TPO Ab-), those with TSH concentrations of 2.5-4.0 mIU/L and TPO Ab- had a 0.65-fold lower risk of low birth weight (LBW). In contrast, those with TSH concentrations of >4.0 mIU/L, regardless of the TPO Ab status, had a 2.01-fold increased risk of LBW. Subclinical hypothyroidism, regardless of the TPO Ab status, was associated with a 1.94-fold higher risk of LBW when compared with that in subjects with euthyroidism and TPO Ab-. No other significant associations were observed.

CONCLUSION

A maternal TSH concentration of 2.5-4.0 mIU/L was associated with a lower risk of LBW when combined with TPO Ab-, whereas subjects with a TSH concentration of >4.0 mIU/L had an increased risk of LBW. Subclinical hypothyroidism appears to be associated with a higher risk of LBW.

Associations between thyroid-stimulating hormone, blood pressure and adiponectin are attenuated in children and adolescents with overweight or obesity

Background The association between thyroid-stimulating hormone (TSH) concentrations and blood pressure is well described in adults, but only studied to a limited extent in children and adolescents and almost entirely in population-based cohorts. The present study investigates the association between TSH and blood pressure, and the influence of leptin and adiponectin, in a cohort of children and adolescents enrolled in obesity treatment compared with a population-based cohort. Methods We studied 4154 children and adolescents aged 6-18 years from an obesity clinic cohort and a population-based cohort from The Danish Childhood Obesity Data- and Biobank. Anthropometrics, blood pressure and biochemical markers, including TSH, leptin and adiponectin concentrations, were collected. Adjusted correlation and interaction analyses were performed. Results Patients from the obesity clinic cohort exhibited higher concentrations of TSH and higher blood pressure than participants from the population-based cohort. TSH standard deviation scores (SDS) were significantly associated with all blood pressure-related variables in the population-based cohort, but only with systolic blood pressure SDS and hypertension in the obesity clinic cohort. The interaction between TSH SDS and adiponectin was found to be independently associated with systolic blood pressure and hypertension in the population-based cohort only. Conclusions The significant associations between TSH, adiponectin and blood pressure, observed in children and adolescents from a population-based cohort, are attenuated or absent in children and adolescents with overweight or obesity, suggesting that childhood obesity distorts the healthy interplay between the thyroid axis, thyroid-adipokine interaction and blood pressure.

Seizure duration may increase thyroid-stimulating hormone levels in children experiencing a seizure

Objective

Variations in hormone levels are a direct effect of epileptic discharges in both animals and humans, and seizure can affect the hypothalamus–pituitary–thyroid axis. The purpose of this study was to determine which parameters could affect the alternation of thyroid hormones in children experiencing seizure.

Methods

We retrospectively reviewed the medical records of 181 pediatric patients with seizure and compared three thyroid hormones (serum thyroid-stimulating hormone [TSH], free thyroxine [fT4], and triiodothyronine [T3]) between initial (admission to hospital) and follow-up (2 weeks later) testing.

Results

Multivariable logistic regression models were used to determine which six parameters (gender, age, seizure accompanying with fever, seizure type, seizure duration, and anti-epileptic drug medication) could help to explain the higher initial TSH levels in pediatric seizure. Only seizure duration in patients with an increase in TSH levels was significantly longer compared with patients with normal TSH at the time of initial testing.

Conclusion

Neuronal excitability by seizure can cause thyroid hormonal changes, which likely reflects changes in hypothalamic function.

Carboxyl Esterase-Like Activity of DT-Diaphorase and Its Use for Signal Amplification

Carboxyl esterases show limited use as catalytic labels in bioassays because of slow enzymatic reaction. We report that DT-diaphorase from Bacillus stearothermophilus (DT-D, EC 1.6.99.-) shows high carboxyl esterase-like activity in the presence of reduced β-nicotinamide adenine dinucleotide (NADH) and may be used as a better catalytic label than carboxyl esterases. DT-D is a redox enzyme and can participate in signal-amplifying redox cycling. Thus, an electrochemical immunosensor using a DT-D label allows for triple signal amplification based on (i) hydrolysis of a carboxyl ester, (ii) electrochemical-chemical (EC) redox cycling involving an electrode, a hydrolysis product, and NADH, and (iii) electrochemical-enzymatic (EN) redox cycling involving an electrode, a hydrolysis product, DT-D, and NADH. Ester hydrolysis by DT-D is confirmed via spectrophotometric measurement of a chromogenic substrate (4-nitrophenyl acetate) and ¹H NMR spectra. Among two phenyl acetates and four naphthyl acetates considered, 4-aminonaphthalene-1-yl acetate (4-NH₂-NAc) is chosen as the best acetyl ester substrate because 4-NH₂-NAc is stable, its hydrolysis is slow in the absence of DT-D, its hydrolysis is very fast in the presence of DT-D, and EC and EN redox cycling involving the hydrolysis product (4-amino-1-naphthol) is rapid. However, hydrolysis of 4-NH₂-NAc by esterase from porcine liver (EC 3.1.1.1.) is very slow. When DT-D is applied to sandwich-type detection of thyroid-stimulating hormone in artificial serum, the detection limit is ∼2 pg/mL, indicating that the developed immunosensor is highly sensitive because of triple signal amplification. DT-D may be used as a catalytic label in sensitive and stable bioassays instead of common alkaline phosphatase and horseradish peroxidase.

The Pathogenic TSH β-subunit Variant C105Vfs114X Causes a Modified Signaling Profile at TSHR

1) Background: Central congenital hypothyroidism (CCH) is a rare endocrine disorder that can be caused by mutations in the β-subunit of thyrotropin (TSHB). The TSHB mutation C105Vfs114X leads to isolated thyroid-stimulating-hormone-(TSH)-deficiency and results in a severe phenotype. The aim of this study was to gain more insight into the underlying molecular mechanism and the functional effects of this mutation based on two assumptions: a) the three-dimensional (3D) structure of TSH should be modified with the C105V substitution, and/or b) whether the C-terminal modifications lead to signaling differences. 2) Methods: wild-type (WT) and different mutants of hTSH were generated in human embryonic kidney 293 cells (HEK293 cells) and TSH preparations were used to stimulate thyrotropin receptor (TSHR) stably transfected into follicular thyroid cancer cells (FTC133-TSHR cells) and transiently transfected into HEK293 cells. Functional characterization was performed by determination of Gs, mitogen activated protein kinase (MAPK) and Gq/11 activation. 3) Results: The patient mutation C105Vfs114X and further designed TSH mutants diminished cyclic adenosine monophosphate (cAMP) signaling activity. Surprisingly, MAPK signaling for all mutants was comparable to WT, while none of the mutants induced PLC activation. 4) Conclusion: We characterized the patient mutation C105Vfs114X concerning different signaling pathways. We identified a strong decrease of cAMP signaling induction and speculate that this could, in combination with diverse signaling regarding the other pathways, accounting for the patient's severe phenotype.

Thyroid-stimulating hormone is associated with nonalcoholic steatohepatitis in patients with chronic hepatitis B

The relationship of thyroid function parameters with nonalcoholic steatohepatitis (NASH) in patients with chronic hepatitis B (CHB) remains unknown. Hence, we assessed the impact of thyroid function parameters on NASH in patients with CHB.Consecutive patients with CHB with concurrent nonalcoholic fatty liver disease (NAFLD) were recruited. Liver histology and baseline examinations were carried out in each patient. The associated risk factors for NASH were evaluated.A total of 361 patients with CHB with biopsy-proven NAFLD were included. There was a significant difference in the serum thyroid-stimulating hormone (TSH) level between patients with NASH and non-NASH (3.24 ± 2.00 vs 2.05 ± 1.35 mIU/L, P < .01). Moreover, the NASH prevalence in patients with euthyroidism was significantly higher than in the subclinical hypothyroidism (SCH) patients (P < .001). In multivariate analyses, higher serum concentration of TSH was significantly correlated with NASH (odds ratio [OR]: 1.69, 95% confidence interval [CI]: 1.24-2.31; P = .001). In particular, patients suffering from SCH had a higher risk of having NASH (OR: 4.28, 95% CI: 1.18-15.53; P = .027).Elevated serum TSH level was the independent predictive factor of incident NASH in patients with CHB. Whether the thyroid function parameters should be integrated into future diagnostic scores predicting advanced diseases requires further study.

[Thyroid antibodies levels in euthyroid men and women - residents of the Arctic Zone of the Russian Federation.]

The aim of the study was to determine the levels of thyroid antibodies and their relationship with thyroid hormones and thyroglobulin in euthyroid men and women, residents of the Arctic zone of the Russian Federation. A total of 208 apparently healthy people were enrolled in this study and classified into two groups depending on gender and level of autoantibodies in the blood. Serum hormones of the pituitary-thyroid system, thyroglobulin and antibodies concentration was measured by enzyme immunoassay. The prevalence of positive antibodies among various examined groups was determined and the characteristics of euthyroid subjects with abnormal thyroid antibodies levels were studied. Circulating positive thyroid antibodies were found in 20% of the surveyed residents of the Arctic zone of the Russian Federation. The median serum antibodies against thyroid peroxidase (AntiTPO) or thyroglobulin (AntiTG) levels and the percentage of people in general population with positive antibodies (i.e. AntiTPO ≥ 50 IU / ml and / or AntiTG ≥ 100 IU / ml) were statistically significant higher in women than in men, p < 0.01. Such thyroid antibodies levels were associated with a higher thyroid gland functional activity in women, which was demonstrated by significantly higher thyroxin level and lower thyroglobulin value in the peripheral blood. Part of women positive for AntiTPO increased with age from 18 to 33% (in groups aged 18-44 and 45-59 years, p = 0.04). The findings of the study reveal correlation between thyroid function test and thyroid antibodies levels, elaborating the clinical importance of thyroid antibodies in clinical examination and follow-up of patients with autoimmune thyroid disorders.

Pattern Reversal Visual Evoked Potential and Cognitive Functions in Subclinical Hypothyroid Subjects

Background:

Central nervous system (CNS) involvement is insidious and may occur early in subclinical hypothyroid (SCH) state which can be picked up by electrophysiological study. This study aims to record visual evoked potential (VEP), event-related latency and cognitive functions, and find their association with the levels of serum thyroid-stimulating hormone (TSH) in patients with SCH.

Materials and Methods:

In this cross-sectional study, 36 adult SCH patients and an equal number of age- and sex-matched euthyroid controls were included. Pattern reversal VEP, visual reaction time (RT), digit spanning test, and AB clock test (ABCT) were done in both SCH cases and euthyroid controls. The observed values were analyzed for comparison of mean values between the groups and correlation of recorded variables with the levels of serum TSH.

Results:

SCH cases showed a higher P100 (VEP) latency in both the right (103.2 ± 12.3 vs. 102.7 ± 6.8 ms) and left eye (101.1 ± 9.1 vs. 96.2 ± 10.7 ms) as compared to controls, but the difference was statistically insignificant. A significant delay in RT was observed on visible spectra of light in SCH cases (P < 0.001). Digit spanning score (forward and backward) in SCH cases was significantly lower than controls (P < 0.001), and a lower standardized score (<124 or <95^th percentile) was significantly associated with SCH state (P = 0.027). No significant difference was observed in visuospatial domain by ABCT between both the groups although the median score was lower in SCH cases. Only digit spanning score showed a significant negative correlation with TSH levels (r = −0.4; P = 0.001).

Conclusion:

Decline in working memory and RT to visual stimuli is an evidence of the involvement of CNS in SCH. Prolonged latency in VEP may depend on the duration of SCH.

Physiological and Pathological Role of Circadian Hormones in Osteoarthritis: Dose-Dependent or Time-Dependent?

Osteoarthritis (OA), the most common form of arthritis, may be triggered by improper secretion of circadian clock-regulated hormones, such as melatonin, thyroid-stimulating hormone (TSH), or cortisol. The imbalance of these hormones alters the expression of pro-inflammatory cytokines and cartilage degenerative enzymes in articular cartilage, resulting in cartilage erosion, synovial inflammation, and osteophyte formation, the major hallmarks of OA. In this review, we summarize the effects of circadian melatonin, TSH, and cortisol on OA, focusing on how different levels of these hormones affect OA pathogenesis and recovery with respect to the circadian clock. We also highlight the effects of melatonin, TSH, and cortisol at different concentrations both in vivo and in vitro, which may help to elucidate the relationship between circadian hormones and OA.